Q. positive divided by a negative equals
Answer
Let \(x>0\) and \(y>0\). Consider \( -x + y \).
– If \(y > x\): \( -x + y = y – x > 0\) (positive).
– If \(y = x\): \( -x + y = 0\).
– If \(y < x\): \( -x + y = -(x - y) < 0\) (negative).
Detailed Explanation
Explanation
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State what “positive divided by a negative” means.
Let \( a \) be a positive number and \( b \) be a negative number, so that \( a > 0 \) and \( b < 0 \).
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Rewrite division as multiplication by the reciprocal.
Division can be written as multiplication by the reciprocal. Thus:
\[ \frac{a}{b} = a \cdot \frac{1}{b} \]
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Determine the sign of the reciprocal.
The reciprocal of a negative number is also negative. Since \( b \) is negative, \( \frac{1}{b} \) is negative.
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Multiply a positive by a negative.
A positive number multiplied by a negative number gives a negative result. Therefore:
\[ a \cdot \frac{1}{b} \text{ is negative.} \]
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Conclude the sign of the quotient.
Combining the previous steps,
\[ \frac{a}{b} \text{ is negative.} \]
In words: a positive number divided by a negative number equals a negative number.
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Example for clarity.
Take \( a = 6 \) and \( b = -2 \). Then:
\[ \frac{6}{-2} = 6 \cdot \frac{1}{-2} = 6 \cdot \left(-\tfrac{1}{2}\right) = -3. \]
This confirms the rule: positive divided by negative is negative.
FAQs
What is a positive divided by a negative?
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